Sep 30, 2013

Understanding estrogen and its effect on cognition

By

Erin Howe

For Dr. Gillian Einstein, it’s a thrill to know her work on women’s brain health will help people make more informed decisions about their bodies.

“It’s really what I always wanted to do. I always wanted to work on scientific problems that would make a difference,” she says.

Einstein is an Associate Professor with the University of Toronto’s Department of Psychology and the Dalla Lana School of Public Health.  She is also the Director of the Collaborative Graduate Program in Women’s Health.

Her lab is exploring what happens to cognition in women who carry specific mutations to the genes, BRCA1 and 2, and have had their ovaries removed in a procedure known as an oophorectomy. This leaves a woman’s body unable to produce one critically important estrogen, 17-beta-estradiol.

BRCA1 and BRCA2 are DNA repair genes, but when they contain mutations, they can be linked to increased rates of breast and ovarian cancers. Some women who learn they carry these mutations choose to have their ovaries removed to reduce their risk of cancer.

But, Einstein explains, there can be other consequences.

Earlier research has found that women who’ve had their ovaries removed faced a higher incidence of Alzheimer’s and Parkinson’s dementias than women who still had their ovaries.

Now, Einstein is trying to find out why.

Her research has involved three groups of women: a group that carries the BRCA mutation and have kept their ovaries, a group that carries the mutation and have had their ovaries removed, and a group of similarly aged women who aren’t carriers of the gene mutation.

To gather the information, the lab is recruiting women one to eight years after surgery and testing them three times in the following years.  This will generate data spanning a decade.

The research is ongoing, but preliminary findings reveal that following ovary removal, the ability to remember words declines as time passes. Logical memory, which can determine how well a person generally remembers things, may also be affected in some people.

Einstein expects to have some definitive results by the end of 2014.

The project will soon allow Einstein to recruit women prior to their surgeries, and to test them before and after the operation as well as a few years later. This will establish better benchmarks by which to compare the results. Einstein will also be collaborating with the Rotman Research Institute at Baycrest to do brain imaging as part of her research.

“I’d very much like women who are electing to have ovaries removed — for very good reasons I might add — to have a full sense of what is going to follow,” says Einstein. “They should know that while it will decrease their risk of ovarian cancer, there may also be some cognitive declines.”

She adds that removing the ovaries can also have implications for bone and heart health, as well as the immune system. Einstein’s hope is for women and doctors appreciate that removing the ovaries doesn’t only affect the reproductive system, but the entire body.

“Estrogen is an incredible molecule, and it does amazing things in both men and women’s bodies,” says Einstein.  “I think the women with the BRCA mutation are making an enormous contribution to our understanding [of estrogen].”


U of T Medicine’s Brain Health and Neuroscience Network spans nine hospitals, 250 scientists and includes $98-million in research funding.  To learn more about the Network, click here.